<?php
// File name:	rfc822.inc.php
// Description:	PHP subroutine for RFC 822 address related patterns
// Date:	2004-02-11
// Author:	imacat <imacat@pristine.com.tw>
// Copyright:	Copyright (C) 2004-2007 Pristine Communications

define("RFC822_CTL", "[\\x01-\\x1F\\x7F]");
define("RFC822_SPECIALS", "[()<>@,;:\\\\\".\\[\\]]");
define("RFC822_ATOM", "[\\x21\\x23-\\x27\\x2A-\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x41-\\x5A\\x5E-\\x7E]+");
define("RFC822_DTEXT", "[^\"\\\\\r]");
define("RFC822_QUOTED_PAIR", "\\\\[\\x01-\\xFF]");

define("RFC822_DOMAIN_REF", RFC822_ATOM);
define("RFC822_DOMAIN_LITERAL", "\\[(?:" . RFC822_DTEXT . "|" . RFC822_QUOTED_PAIR . ")*\\]");
define("RFC822_SUB_DOMAIN", "(?:" . RFC822_DOMAIN_REF . "|" . RFC822_DOMAIN_LITERAL . ")");
define("RFC822_DOMAIN", RFC822_SUB_DOMAIN . "(?:\." . RFC822_SUB_DOMAIN . ")*");
define("RFC822_QUOTED_STR", "\"(?:" . RFC822_DTEXT . "|" . RFC822_QUOTED_PAIR . ")*\"");
define("RFC822_WORD", "(?:" . RFC822_ATOM . "|" . RFC822_QUOTED_STR . ")");
define("RFC822_LOCAL_PART", RFC822_WORD . "(?:\." . RFC822_WORD . ")*");

define("RFC822_ADDR_SPEC", RFC822_LOCAL_PART . "@" . RFC822_DOMAIN);

// rfc822_phrase_need_quoting: Whether a phrase need to be quoted by RFC-822
function rfc822_phrase_need_quoting($a)
{
    return preg_match("/[()<>@,;:\\\\\".\\[\\]\\x01-\\x1F\\x7F]/", $a)?
        true: false;
}

?>